Method and apparatus for selecting the operational mode of an integrated circuit

An integrated circuit having a first and second mode of operation, said integrated circuit being powered by at least one supply voltage, said integrated circuit comprising:

• a power bus configured for being electrically interconnected to the at least one supply voltage;
• and
• an operational mode logic circuit electrically connected to said power bus, said operational mode logic circuit monitoring a voltage level of the power bus, an operational mode signal being issued by said operational mode logic circuit dependent at least in part upon the occurrence of a predetermined sequence of the voltage level on said power bus, said operational mode signal being active and placing said integrated circuit into the second mode of operation when said predetermined sequence of voltage levels occurs on said power bus, said operational mode signal being inactive and placing said integrated circuit into the first mode of operation when said predetermined sequence of voltage levels does not occur on said power bus.